### Author Topic: PIPES AND CISTERNS (capacity of cistern)  (Read 4271 times)

#### Mohd Liyaqat Hussain

• Newbie
• Posts: 6
##### PIPES AND CISTERNS (capacity of cistern)
« on: February 10, 2014, 10:04:34 AM »
daniel bro...
again you have to solve a problem for me
Q) Two pipes can fill a tank in 20 and 24 minutes respectively and a waste pipe can empty 3 gallons per minute.All the three pipes working together can fill the tank in 15 minutes.the capacity of the tank is..........

a)60 gallons
b)100 gallons
c)120 gallons
d)180 gallons

#### Bibhudas

• Newbie
• Posts: 6
##### Re: PIPES AND CISTERNS (capacity of cistern)
« Reply #1 on: February 21, 2014, 11:11:33 AM »
Hi , I would like to try it
as u know in 1 minute  pipe A and B can fill 1/20 and 1/24 respectively,and pipe C can empty 1/x  ,in the question it's also given that all the three working at a time can fill the tank in 15 minutes.
We can frame an equation 1/20 +1/24 -1/x=1/15 ,after solving it we get x=40

pipe C can empty the tank at a rate of 3 gallons per minute so capacity of the tank is 40*3=120 gallons.

Thanks
It's all over to Daniel

• Daniel